1. Technical Field
The technical field of this disclosure relates generally to segmenting objects from light field data, for example as obtained by plenoptic cameras or camera arrays.
2. Description of the Related Art
Object segmentation from light field images has not been studied much in the past. A few approaches perform analysis of epipolar plane images to separate them into layers, where each layer is a collection of pixels corresponding to scene features present at a certain depth plane. In some approaches, the segmentation is based on the assumption that each layer in the light field corresponds to a three-dimensional (3D) plane placed fronto-parallel to the camera, i.e., at a constant depth. Researchers have also introduced the concept of occlusions by using masking function for visible and non-visible regions of the image. In one approach, the segmentation is based on active contours using the level-set method. In another approach, the layers are separated by modeling the light field as a non-linear combination of layers represented by a sparse decomposition. However, the assumption of constant depth across a layer would be violated in most real-world scenes.
An approach not restricted to planar depth layers introduces a variational labeling framework on ray space. The segmentation is defined as an energy minimization using regularization in the epipolar plane images, to encourage smoothing in the direction of rays present in epipolar plane images and in the spatial domain (enforce the label transition costs). Other approaches use oriented windows and the simple linear interactive clustering (SLIC) super pixel segmentation method to perform segmentation.
However, all of these approaches have drawbacks.